Sealed contact makers including diaphragms for closing contacts



Filed July 27, 1966 June 16, 1967 D. s. RIDLER ETAL 3,3 3

SEALED CONTACT MAKERS INCLUDING DIAPHRAGMS FOR CLOSING CONTACTS F/GZ 2 Sheets-Sheet l S. RIDLER ETAL D. SEALED CONTACT Filed July 2'7, 1966 June 6, 1967 I MAKERS ncwnme DIAPHRAGMS F cnosme CONTACTS 2 Sheets-Sheet 2 United States Patent 3,324,432 SEALED CUNTACT MAKERS INCLUDING DIA- PHRAGMS FOR CLOSING CONTACTS Desmond Sydney Ridler, Edward Ronald Myatt, and Ernest Frederick Loveland, London, England, assignors to International Standard Electric Corporation, New York, N.Y., a corporation of Delaware Filed July 27, 1966, Ser. No. 571,678. Claims priority, application Great Britain, Aug. 27, 1965, 36,916/ 65 13 Claims. (Cl. 335-151) This invention relates to sealed contact devices i.e. devices having contact making members hermetically sealed inside an enclosure, particularly for usein light current electromagnetic relays.

According to the invention there is provided a sealed multiple con-tact device which includes, within a hermetically sealed enclosure, a flat resilient plate of ferromagnetic metal having a peripheral area which is sealed into the enclosure and a plurality of inwardly extending tongues, a contact .area of electrically conductive material carried on each tongue and insulated therefrom by a layer of electrically insulating material, and two fixed contacts of electrically conductive material for each tongue sealed through the enclosure and located so that upon the application of magnetic flux through the device the tongues move and each contact area bridges its corresponding two fixed cont-acts to provide an electrical path between them.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a plan view of a relay, with the top cap removed,

FIG. 2 shows a cross-sectional view, along the line AA, of the relay shown in FIG. 1, and

FIG. 3 shows a plan view of an alternative magnetic plate to the one shown in FIG. 1.

Referring now to FIGS. 1 and 2, eight fixed contacts in the form of rods of ferromagnetic electrically conductive material are sealed into an annulus 11 of ferromagnetic material by a glass disc 12. The ends of the rods are suitably treated, e.g. with a precious metal, to give a good electrical contact. The rods 10 are positioned centrally around the axis of the annulus 11, and the glass seal 12 closes one side of the aperture through the annulus 11. A flat resilient plate 13 of ferromagnetic metal is clamped between the annulus 11 and an outer cap 14 of ferromagnetic material and sealed e.g. by welding so that the cap 14 closes the other side of the aperture through the annulus 11. The cap 14, the annulus 11 and the glass seal 12 thus form .a hermetically sealed enclosure within which are sealed the rods 10 and the plate 13.

The plate 13 has a plurality of slots of small width relative to their length which divide the plate into a peripheral area 15 and four inwardly projecting tongues 16. Each tongue 16 is very roughly shaped like a silhouette of a rocking chair, and has an area 17, on its side facing the rods 10, on which is deposited a layer of electrically insulating material e.g silicon monoxide. A layer of metal is deposited over the insulating layer and a contact area of precious metal is built up on the metal layer. The rods 10 are arranged in pairs, one pair for each tongue 16, so that their ends are normally separated by a small distance from the contact areas on the plate 13.

A coil 18 surrounds the rods 10, and a casing 19 of magnetic material is secured to the annulus 11 and surrounds the coil 18 leaving a hole through which the rods 10 project.

When the coil 18 is energised, a magnetic flux is set up in the rods 10 which bridges the gap between the rods 10 and the plate 13 and finds a return path partly via the ice plate 13 and partly via the cap 14, then via the annulus 11 and the magnetic casing 19. When the flux in the gap between the plate 13 and the rods 10 is large enough, the tongues 16 move towards the rods 10 and each contact area bridges its corresponding two rods to provide an electrical path between them. The electrical paths through each pair of rods 10 are isolated from each other by the insulating material on the contact areas 17. When the coil 18 is de-energised the resilient tongues move back to their rest position and the electrical path between each pair of rods is broken. J

Thus the plate 13 is included in the operating magnetic circuit of the relay, but is not included in the electrical circuits completed by the relay. Insulating material could, alternatively, be deposited over the whole free surface of the plate 13 instead of individually over each contact area 17.

Other arrangements of fixed contact rods can be used, for example each pair of contact rods could be on a radial line of the plate. Furthermore, it is not essential that the fixed contact rods 10 be of ferromagnetic material, although this is preferred, The magnetic flux could be carried into the sealed enclosure by one or more rods of ferromagnetic material separate from the fixed contact rods 10. Also, other patterns of tongues formed in the plate could be used. For example, FIG. 3 shows a plate 13 in which the four tongues are joined together at their inward ends to help maintain equality in the air gaps. The pattern of slots in the plate 13 is arranged to give thenecessary flexibility and twist in the tongues to give adaquate contact pressure on the rods 10.

A 4-make relay as in the above-described embodiments is particularly useful as a crosspoint switch in telephone exchanges.

In the embodiments described above the plate 13 has four inwardly projecting tongues. The invention is not limited to this number of tongues as a plate could also be suitably slotted to provide two, three or more than four tongues and a corresponding number of fixed contact rods would be provided in each case. Furthermore, in the embodiments described above, the plate 13 has been divided up by a plurality of slots of small width relative to their length. This is done so that the high proportion of the plate area which is left provides low reluctance paths for the magnetic flux which operates the relay. However, it is not essential to form the tongues in this manner so long as there is a plurality of inwardly projecting tongues integral with a peripheral area of the plate.

It is to be understood that the foregoing description of specific examples of this invention is made by way of example only and is not to be considered as a limitation on its scope.

What we claim is:

1. A sealed multiple contact device which includes, within a hermetically sealed enclosure, a fiat resilient plate of ferromagnetic metal having a peripheral area which is sealed into the enclosure and a plurality of inwardly extending tongues, a contact area of electrically conductive material carried on each tongue and insulated therefrom by a layer of electrically insulating material, and two fixed contacts of electrically conductive material for each tongue sealed through the enclosure and located so that upon the application of magnetic flux through the device the tongues move and each contact area bridges its corresponding two fixed contacts to provide an electrical path between them.

2. A device as claimed in claim 1, in which the plate has a plurality of slots of small width relative to their length, which slots divide the plate into the peripheral area and the plurality of tongues.

3. A device as claimed in claim 1, in which the tongues are joined together at their inner ends.

4. A device as claimed in claim 2, in which at least part of the hermetically sealed enclosure is formed of ferromagnetic material.

5. A device as claimed in claim 4, in which the hermetically sealed enclosure includes an annulus of ferro magnetic material, in which one side of the aperture through the annulus is closed by a cap which seals the periphery of the plate to the annulus, and in which the other side of the aperture through the annulus is closed by a seal through which the fixed contacts project.

j 6." A device as claimed in claim 5, in which the cap is of ferromagnetic material.

7. A device as claimed in claim 6, in which the fixed contacts are of ferromagnetic material.

8. A light-current electromagnetic relay Which includes a sealed multiple contact device as claimed in claim 6, in which the fixed contacts are a group of ferromagnetic rods positioned centrally around the axis of the annulus and passing through the centre of an operat ing coil outside the hermetically sealed enclosure.

9. An electromagnetic relay as claimed in claim 8, in which a casing of magnetic material surrounds the coil and provides a path for magnetic flux from the annulus to the ends of the fixed contact rods away from the annulus.

10. An electromagnetic relay as claimed in claim 9, in which there are four tongues and the relay is a 4-make relay.

11. A light-current electromagnetic relay which includes a hermeticallysealed enclosure, a first resilient plate of ferromagnetic metal within the enclosure, the

plate having a peripheral area which is sealed into the enclosure and a plurality of inwardly extending tongues, a contact area of electrically conductive material carried on each tongue and insulated therefrom by a layer of electrically insulating material, two fixed contacts in the form of rods of electrically conductive material for each tongue sealed through the enclosure and located with their ends inside the enclosure separated from the corresponding tongue by a small distance, and a coil arranged outside the enclosure so that upon its energisation of magnetic flux path is set up through the enclosure which causes the tongues to move and the contact areas to bridge their corresponding pairs of fixed contacts and provide electrical paths between them.

12. A relay as claimed in claim 11, in which the fixed contact rods are of ferromagnetic material and pass through the centre of the coil outside the hermetically sealed enclosure.

13. A relay as claimed in claim 12, in which there are four tongues and the relay is a 4-make relay.

References Cited UNITED STATES PATENTS 2,752,450 6/1956 Foulkes et a1. 335196 X 2,933,571 4/1960 Howell 200144 X 3,150,244 9/1964 Nits-ch- 335196 X FOREIGN PATENTS 1,021,047 5/ 1963 England.

BERNARD A. GILHEANY, Primary Examiner.

R. N. ENVALL, Assistant Examiner. 

1. A SEALED MULTIPLE CONTACT DEVICE WHICH INCLUDES, WITHIN A HERMETICALLY SEALED ENCLOSURE, A FLAT RESILIENT PLATE OF FERROMAGNETIC METAL HAVING A PERIPHERAL AREA WHICH IS SEALED INTO THE ENCLOSURE AND A PLURALITY OF INWARDLY EXTENDING TONGUES, A CONTACT AREA OF ELECTRICALLY CONDUCTIVE MATERIAL CARRIED ON EACH TONGUE AND INSULATED THEREFROM BY A LAYER OF ELECTRICALLY INSULATING MATERIAL, AND TWO FIXED CONTACTS OF ELECTRICALLY CONDUCTIVE MATERIAL FOR EACH TONGUE SEALED THROUGH THE ENCLOSURE AND LOCATED SO THAT UPON THE APPLICATION OF MAGNETIC FLUX THROUGH THE DEVICE THE TONGUES MOVE AND EACH CONTACT AREA BRIDGES ITS CORRESPONDING TWO FIXED CONTACTS TO PROVIDE AN ELECTRICAL PATH BETWEEN THEM. 